In recent years, several structures have been equipped with permanent monitoring systems, able to record the response both in terms of displacements and strains over very long periods of time and, theoretically, for the entire life of the structure. Despite of the number of applications, very few studies have been presented focused on the interpretation of the data without the study of a numerical model of the structure. Since an optimal and unique algorithm cannot be proposed depending on the variety of applications, the aim of the work is to propose a multi-algorithm methodology as a tool for detecting and localizing the insurgence of damage or material degradation from the measurements taken during a continuous static monitoring of civil structures. A method based on Principal Component Analysis will be proposed in order to compare the responses and detect the insurgence of anomalous behaviors. The algorithm will be first tested on simulated data deriving from a numerical benchmark with sensors and different damage scenarios, then the proposed methodology will be validated on a real structure. In this second application, due to the great number of installed sensors, the algorithm will be integrated with a preliminary analysis in order to cluster and gather together the sensors with a comparable behavior and a similar sensitivity to damage.